In semiconductor devices such as CSP's and BGA's, bumps have hitherto been used as terminals for mounting on circuit boards such as mother boards and daughter boards. Techniques which have been employed for improving the reliability of connection with the bumps include a method in which a resin is applied only to around the bottoms of bumps to reinforce the bumps (referrence 1) and a method in which a bump-reinforcing film having holes formed beforehand in areas where bumps are to be located is applied to a circuit board before bumps are formed thereon (reference 2).                Reference 1: WO 02/24391        Reference 2: JP-A-2000-208547        
However, in the former method, there is a possibility that the resin might be applied unevenly because of the pitch and positions of bumps, etc. In the areas in which the resin has been applied in an insufficient amount, a deficiency in reinforcement results to cause unevenness in the improvement of connection reliability. In addition, there is a problem that the production steps are complicated and this increases the cost of semiconductor devices.
In the latter method, it is necessary to form through-holes beforehand in a reinforcing sheet according to the positions and size of bumps. There is hence a possibility that connection reliability might be adversely influenced by the shape and positions of the through-holes formed. Furthermore, there is a problem that the production steps are complicated, resulting in an increased cost.